The Crawley family in Downton Abbey suffers from a lack of estate planning. The most obvious estate planning lesson from the show is to diversify your holdings. In the show, the head of the Crawley family invests most of his wife's fortune in a Canadian railway that goes bankrupt).The other tips Wall Street Journal points out are below:

1. Sell the house: The Crawley family tries to find ways to keep control of their sprawling estate. However, in reality, inheriting a house can be more trouble than it is worth and it might be best to sell the property and inherit the cash.

2. Use trusts to protect a family fortune: Dynasty trusts can help protect assets against bad management. Specifically, these trusts can prevent one person from blowing a family fortune. Such a trust may have been able to prevent the Earl of Grantham from putting nearly all of the family's funds into one venture that ended poorly.

3. Set up a medical directive: In Downton Abbey, characters are regularly dying, and this highlights the need for a will and advance medical directives.

Last, don't keep so many secrets as secrets are often detrimental to proper estate planning.